12 DataTable table = ds.Tables[0]; 13 14 15 DataSet 可以盛放多个查询结果集到DataTable ;DataAdapter还可以对结果进行傻瓜化更新...我们一般查询结果集就一个DataTable, DataAdapter的傻瓜化更新不适合于正式的项目,因此有更简单的用法 16 17 DataTable dt = new DataTable(); 18...} public static int ExecuteNonQuery(MySqlConnection conn, string sql, params MySqlParameter...ExecuteQuery意思是 执行查询 返回值是 一张二维表,,,ExecuteNonQuery意思是 执行非查询,即:插入,更新,删除操作 返回值是影响的行数,即整形 int B7第七章...5 6 7 using (MySqlConnection conn = MySqlHelper.CreateConnection()) 8 { 9 MySqlHelper.ExecuteNonQuery
MySsqlCommand MySqlCommand cmd = new MySqlCommand(sql, sqlCon); //执行SQL cmd.ExecuteNonQuery...MySqlCommand cmd = new MySqlCommand(sql, sqlCon); //执行SQL int updateCount=cmd.ExecuteNonQuery...MySqlCommand cmd = new MySqlCommand(sql, sqlCon); //执行SQL int updateCount=cmd.ExecuteNonQuery...(); if (updateCount > 0) { Response.Write("更新成功"); } else...{ Response.Write("更新失败"); } cmd = null; sqlCon.Close();
MySql.Data.dll提供以下8个类: MySqlConnection: 连接MySQL服务器数据库。 MySqlCommand:执行一条sql语句。...{ Console.WriteLine(ex.Message); } finally { conn.Close(); } 3.捕捉异常(MySqlException类) 连接错误时...ExecuteNonQuery——用于插入、更新和删除数据。 ExecuteScalar——用于查询数据时,返回查询结果集中第一行第一列的值,即只返回一个值。 ...) values('啊宽','123','" + date + "')"; MySqlCommand cmd1 = new MySqlCommand(sql1,conn); cmd1.ExecuteNonQuery...values('啊宽','123','" + date + "')"; MySqlCommand cmd2 = new MySqlCommand(sql2, conn); cmd2.ExecuteNonQuery
conn = new MySQLConnection(new MySQLConnectionString("localhost", "housing", "root", "root").AsString...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery...MySQLCommand cmd = new MySQLCommand(sql, conn); //返回受影响行数 int number = cmd.ExecuteNonQuery...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery
开发背景 完整代码下载地址:点我下载 优化移步: 《c#中在datagridview的表格动态增加一个按钮方法》 《C#实现多窗口切换:Panel详细教程(亲测)》 文章还在更新,上次更新时间2022...} } else { MessageBox.Show("账号或密码、登录身份错误...else { MessageBox.Show("账号或密码、登录身份错误...this.dataGridView1.Rows[index].Cells[4].Value = rec[4]; } 写好以后,这里出现了报红的错误...答:通过表单传值记录id在新的一个窗口查询一次数据,更新则是用了update 如果做到删除?
MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery...添加参数 cmd.Parameters.AddRange(parameters); return cmd.ExecuteNonQuery...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery...MySQLCommand commn = new MySQLCommand("set names gb2312", conn); commn.ExecuteNonQuery
{ connection.Open(); int rows = cmd.ExecuteNonQuery...connection.Open(); cmd.CommandTimeout = Times; int rows = cmd.ExecuteNonQuery...try { connection.Open(); int rows = cmd.ExecuteNonQuery...this.Parameters = para; this.EffentNextType = type; } } } 添加代码后,Visual Studio编辑器会提示如下图的错误...'Clean content',0,'',NULL,NULL,'\0','1',0); 到这里,看上去我们的配置都完成了,将项目[TsBlog.Frontend]设置为启动项,按F5运行,会得到如下的错误
conn = new MySqlConnection(connectionString)) { PrepareCommand(cmd, conn, null,...conn = new MySqlConnection(connectionString)) { PrepareCommand(cmd, conn, null,...(MySqlConnection conn, CommandType cmdType, string cmdText, params MySqlParameter[] commandParameters...conn = new MySqlConnection(connectionString); // we use a try/catch here because if the method...connection = new MySqlConnection(connectionString)) { PrepareCommand(cmd, connection
ConfigurationManager.ConnectionStrings[keyName].ProviderName; } #endregion public int ExecuteNonQuery...(string sql, params MySqlParameter[] parameters) { int res = 0; using (MySqlConnection...con = new MySqlConnection(connectionString)) { con.Open(); using (MySqlCommand...cmd.Parameters.Add(parameter); } try { res = cmd.ExecuteNonQuery...sb.ToString(), con)) { try { res = cmd.ExecuteNonQuery
using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required, TransOpt)) { MySqlConnection...conn = null; conn = new MySql.Data.MySqlClient.MySqlConnection(ConfigurationManager.ConnectionStrings...conn.Open(); MySqlCommand objCmd; objCmd = new MySql.Data.MySqlClient.MySqlCommand(query1, conn); objCmd.ExecuteNonQuery...(); MySqlConnection conn2 = null; conn2 = new MySql.Data.MySqlClient.MySqlConnection(ConfigurationManager.ConnectionStrings...line MySqlCommand objCmd2; objCmd2 = new MySql.Data.MySqlClient.MySqlCommand(query2, conn2); objCmd2.ExecuteNonQuery
Catalog对应的数据库名称,最后一个参数按照原文中即可 SqlConnection con; //与sqlserver数据库建立的连接(mysql数据库对应的是MysqlConnection...执行的命令对象(mysql对应的MysqlCommand) command.CommandText = sql; int a = command.ExecuteNonQuery...(); con.Close(); return a; } //更新 public int update(User...MySql.Data; using MySql.Data.MySqlClient; namespace ConsoleApp3 { class Program { private MySqlConnection...con; public Program() { con = new MySqlConnection("server = 127.0.0.1; port
: Form { public Form1() { InitializeComponent(); } MySqlConnection..."; private void Form1_Load(object sender, EventArgs e) { conn = new MySqlConnection...values('zyr7','man', 28)"; MySqlCommand cmd = new MySqlCommand(sql1,conn); cmd.ExecuteNonQuery...cmd1.ExecuteNonQuery(); } } } mysql: ?
Navicat for mysql 3、用vs2019新建控制台程序,然后引用MySQL.data.dll文件(创建为Framework形式的控制台引用程序) 4、代码实现 ①初始化连接对象 static MySqlConnection...conn = null; ②在主函数中确定对象的相关参数 conn = new MySqlConnection("server=localhost;User Id = root;password=;Database...MySqlCommand cmd = new MySqlCommand("insert into userinfo set name = 'xixi',age=96", conn);//语句内容 cmd.ExecuteNonQuery...delete from userinfo where id = @id",conn); cmd.Parameters.AddWithValue("id",10); cmd.ExecuteNonQuery...cmd.Parameters.AddWithValue("age", 11); cmd.Parameters.AddWithValue("id", 1); cmd.ExecuteNonQuery
. /// /// 返回MySqlConnection对象 public MySqlConnection...myCon = new MySqlConnection(M_str_sqlcon); return myCon; } #endregion...M_str_sqlstr">SQL语句 public void getmysqlcom(string M_str_sqlstr) { MySqlConnection...MySqlCommand mysqlcom = new MySqlCommand(M_str_sqlstr, mysqlcon); mysqlcom.ExecuteNonQuery...对象 public MySqlDataReader getmysqlread(string M_str_sqlstr) { MySqlConnection
ConnetStr = "server=;port=3306;user=;password=;database="; //数据库链接对象 public static MySqlConnection...Conn = new MySqlConnection(ConnetStr); // 初始化数据库链接 public static void InitConnection...// 如果链接对象不存在,则打开链接 if (Conn == null) { Conn = new MySqlConnection...MySqlDataAdapter(cmd); return da; } //增、删、改操作 public static bool ExecuteNonQuery...InitConnection(); MySqlCommand cmd = new MySqlCommand(sqlStr, Conn); int result = cmd.ExecuteNonQuery
原因:使用KVC赋值时出现的错误,可能没有age1这个key 使用xcode6.1创建的项目, 添加新浪SDK,运行[WeiboSDK registerApp:kAppKey];这一步崩溃,抛出以下...) 解决: sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer 将App 上传到Appstore审核时,提示错误
getConn() { MySqlConnection conn = new MySqlConnection(str); conn.Open();...conn; } //2.关闭连接;关闭的连接对象,所以参数是连接对象 public static void close(){ MySqlConnection...MySqlConnection conn = getConn(); MySqlCommand comm = new MySqlCommand(sql,conn); //sql是从外部传过来的命令语句...int result = comm.ExecuteNonQuery(); return result; } //4.查询操作;参数...MySqlConnection conn = getConn(); MySqlDataAdapter adapter = new MySqlDataAdapter(sql, conn
//using MySql.Data.MySqlClient; MySqlConnection sqlC = new MySqlConnection("server=127.0.0.1;database...sqlC); // MySqlDataReader SqlReader = Sqlquery.ExecuteReader(); 纯数据查询返回 // Sqlquery.ExecuteNonQuery
目前,大部分的主流关系型数据库都提供了主从热备功能,通过配置两台(或多台)数据库的主从关系,可以将一台数据库服务器的数据更新同步到另一台服务器上。...利用数据库的读写分离,Web服务器在写数据的时候,访问主数据库(Master),主数据库通过主从复制机制将数据更新同步到从数据库(Slave),这样当Web服务器读数据的时候,就可以通过从数据库获得数据...events)拷贝到它的中继日志(relay log); PS:从图中可以看出,Slave服务器中有一个I/O线程(I/O Thread)在不停地监听Master的二进制日志(Binary Log)是否有更新...PS:从图中可以看出,Slave服务器中有一个SQL线程(SQL Thread)从中继日志读取事件,并重做其中的事件从而更新Slave的数据,使其与Master中的数据一致。..." + userName + "' where id=" + userId; int result = cmd.ExecuteNonQuery
public void DeleteDataByCrrCode(string crrCode) { lock (lockObj) { using (MySqlConnection...connection = new MySqlConnection(connectionString)) { connection.Open();...deleteCmd.Parameters.AddWithValue("@crrCode", crrCode); deleteCmd.ExecuteNonQuery...connection = new MySqlConnection(connectionString)) { connection.Open();...deleteCmd.Parameters.AddWithValue("@crrCode", crrCode); // 执行删除操作 deleteCmd.ExecuteNonQuery